Japanese Knotweed, An Invasive Species
Japanese Knotweed was introduced to the UK during the Victorian era as an attractive plant, but its invasive root system poses a significant threat to buildings. This plant can even penetrate concrete structures, causing damage. It is recognised by the World Conservation Union as one of the most invasive species globally.
When purchasing a property, Japanese Knotweed should be considered, and it is one of the enquiries made to property sellers through the Law Society Property Information Form, which is part of the National Conveyancing Protocol. Solicitors, property lawyers, and conveyancers are well aware that the presence of Japanese Knotweed raises concerns for property buyers and requires thorough investigation.
Some homeowners may encounter difficulties selling their property if Japanese Knotweed is present. It is crucial to have it assessed and professionally treated as soon as possible. Remediation work can be costly and generally needs to be performed by a registered firm associated with the Property Care Association (PCA) or the Institute of Specialist Surveyors and Engineers (ISSE), offering an insurance-backed guarantee. Most mortgage lenders will require a property-specific, transferable guarantee of at least 10 years.
Mortgage lenders establish their own policies regarding lending on properties affected by Japanese Knotweed, but many banks and building societies have strict lending criteria in this regard.
In 2018, Network Rail faced a claim due to inadequate treatment of Japanese Knotweed on their land. The Court of Appeal ruled that Japanese Knotweed is not only a risk of physical damage to structures but also a natural hazard that affects landowners’ ability to fully utilise and enjoy their property. It is considered an interference with the land’s amenity value. As a land and property owner, you may be held liable to your neighbours for the presence of Japanese Knotweed, even if it has not yet spread to their property.
If you are selling a property, we offer free telephone advice before listing it on the market. We can also assist with enquiries raised by the buyer’s conveyancer during the property sale process.
If you are purchasing a property, rest assured that we will thoroughly investigate this issue, just as we do with other enquiries directed to the seller’s conveyancer. We will provide you, your surveyor, and your mortgage lender with the necessary information to make an informed decision regarding the purchase.
The map below provides an indication of the spread of Japanese Knotweed throughout the UK:
